theres no online feedback form, but there is a discord (to which you hate).
there's a trello/wekan board public I think that has some of these ideas in backlog, but the priority now I assume is getting stuff to work at 100% at all times.
as far as I know, they (the people behind the actual tf2pickup organization) want to have those features when they launch eu pickups, though that's quite a journey I hear.